1G:
Names- NMT, AMPS
Features- NMT (replaced wired telephone)
AMPS (replaced wired telephone)
2G:
Names- GSM, iDEN
Features- GSM (digital quality calls everywhere)
iDEN (Push-to-talk service, international roaming)
2.5G
Names- GPRS, CDMA, EDGE
Features- GPRS (Data layer for GSM)
CDMA (Unified digital data)
EDGE ( Data upgrade to GPRS)
3G
Names- UMTS, CDMA2000
Features- UMTS (Advanced GSM phone system)
1xEV-DO (Advanced CDMA telephone system)
4G
Names- HSDPA
Features- Advanced UMTS system for voice, data transfer